Am 01.11.2012 17:07, schrieb g3zjo:
Hi Joe / LF
On my development system the same input level is required to make
both WSPR and WSJT-X happy. Likewise on my shack computer. For
example, see the screen shot posted at
http://physics.princeton.edu/pulsar/K1JT/WSJTX_WSPR.png
Interesting that when I talk of WSPR levels I refer to WSPR2.
Someone sent me a screen Grab the other day Just like the one you
show, but of WSPR2 and WSJT-X, that grab confirmed that when WSPR2
shows 0dB, WSJTX is right up the top of the scale just like I experience.
Yes, confirmed .. WSJT-X input levels are indicated extremely high (one
or dB below the "60 dB" level), even though the 16-bit integer samples
acquired by another program (here: Spectrum Lab) from the same
soundcard, at the same sampling rate, at the very same time, hardly ever
reach 10 percent of the +/- 32767 integer value range. In other words,
the true audio input level is extremely low (voltage), WSJT-X indicates
it's still too large.
I used a TS-850 for reception, which has a 'constant level' audio output
which could always be connected to any soundcard's "line input" (not
"mic input") with the PC's (windows XP) input volume slider centered.
For WSJT-X, I must crank down that slider, so it's just one single tick
above 'zero'. Only a 12 (or so) bits out of the 16 delivered by the A/D
converter are alive at that setting.
The device is configured for 16 bits / sample, in fact the hardware is
not capable of delivering 24 bits/sample at all.
All the best,
Wolf .
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